QuickMark, who makes a cross-platform barcode scanning app, and which already has an app in the Windows Phone 7 Marketplace, have uploaded this video showing an updated version of their app for Mango which allows real time scanning, much more straightforward than the current version which requires one to take a picture first.
Of course barcode scanning is already built into Bing directly in Mango, but the app should allow access to databases which are not currently searched by Bing, reducing the dreaded “No information found” error one often get when scanning products outside USA.
The current version of QuickMark Lite can handle QR Code, EAN 8/13, Code39, and Code128, is free and can be found in Marketplace here.